Nickel Superalloy Interfacial Oxidation
Nickel superalloy interface oxidation is selective oxidation at grain boundaries and phase boundaries in nickel-base materials at high temperatures. It requires blocking diffusion paths with reactive elements.
Physical-Chemical Mechanism of Action
Oxidation at grain boundaries and phase boundaries of nickel-based materials is a selective process where certain areas are oxidized more than others. This happens due to the different diffusion rates of atomic species and the arrangement of atoms at the interfaces.
Metallurgical Relevance & Welding Risks
This oxidation can lead to local changes in the material structure, which impairs the mechanical properties. It can also cause corrosion and cracks, especially if the material is not treated correctly. Blocking diffusion-induced attack paths with reactive elements is crucial to prevent these effects.
Workshop Practice & Instructions
To avoid nickel superalloy interface oxidation, the following measures should be taken:
• Use reactive elements such as silicon or aluminum to block diffusion-induced attack paths.
• Keep operating temperatures below the critical oxidation point.
• Ensure the material is properly pre-treated and welded.